Arab allies pledge to fight Islamic state group

US Secretary of State John Kerry, left, Italian Foreign Minister Paolo Gentiloni, centre, and UN special envoy for Libya Martin Kobler shake hands after their press conference, following an international conference on Libya at the Ministry of Foreign Affairs in Rome, Sunday, Dec. 13, 2015. Foreign ministers were poised to endorse a U.N.-brokered national unity plan for Libya at a Rome conference aimed at prodding the North Africa country's bickering factions to fulfill their commitment to sign the agreement and abide by its terms. (Mandel Ngan/Pool Photo via AP)

U.S. Secretary of State John Kerry steps off a plane upon arrival at Ciampino Airport near Rome Sunday, Dec. 13, 2015. Kerry is in Rome for a high-level gathering on the crisis in Libya. (Mandel Ngan/Pool Photo via AP)

US Secretary of State John Kerry, right, walks with White House senior advisor Brian Deese, left, and US Special Envoy for Climate Change Todd Stern, centre, to attend a meeting with French Foreign Minister Laurent Fabius during the COP 21 United Nations conference on climate change at Le Bourget, on the outskirts of Paris, on Thursday Dec. 10, 2015. (Mandel Ngan Pool via AP)

U.S Secretary of State John Kerry delivers his speech during a news conference at the COP21 Climate Conference in Le Bourget, north of Paris, France, Wednesday, Dec. 9 2015. Kerry is announcing that the United States will double its commitment to helping vulnerable nations adapt to climate change impacts such as increased extreme weather events. (Mandel Ngan, Pool via AP)

US Secretary of State John Kerry (L) and Russia's Foreign Minister Sergei Lavrov shake hands during a joint press conference at the Kremlin on December 15, 2015 in Moscow. / AFP / POOL / MANDEL NGAN (Photo credit should read MANDEL NGAN/AFP/Getty Images)

US Secretary of State John Kerry (L) shakes hands with Russia's President Vladimir Putin during a meeting at the Kremlin in Moscow on December 15, 2015. / AFP / POOL / MANDEL NGAN (Photo credit should read MANDEL NGAN/AFP/Getty Images)

MOSCOW, RUSSIA - DECEMBER 15: US Secretary of State John Kerry attends a meeting with Russian Foreign Minister Sergei Lavrov (not seen) in Moscow on December 15, 2015. (Photo by Sefa Karacan/Anadolu Agency/Getty Images)

ROME, Dec. 13, 2015-- U.S. Secretary of State John Kerry attends a joint press conference with Italian Foreign Minister Paolo Gentiloni and the UN Secretary-General for Libya Martin Kobler after the International Conference on Libya in Rome, Italy, on Dec. 13, 2015. Representatives of the international community at a Rome conference on Libya endorsed on Sunday a UN-backed deal aimed at bringing Libyan rival factions to a unity government. (Xinhua/Jin Yu via Getty Images)

PARIS, FRANCE - 2015/12/09: U.S. Secretary of State John Kerry delivers press remarks at the Caring for Climate Business Forum during the COP21 the World Climate Change Conference in Paris. (Photo by Jonathan Raa/Pacific Press/LightRocket via Getty Images)

US Secretary of State John Kerry speaks at a UN Foundation breakfast meeting on oceans at a hotel in Paris on December 8, 2015 on the sidelines of the COP21 climate change conference. / AFP / POOL / MANDEL NGAN (Photo credit should read MANDEL NGAN/AFP/Getty Images)

US Secretary of State John Kerry boards a plane to return to Washington, at the International Airport in Athens, on December 4, 2015. / AFP / POOL / JONATHAN ERNST (Photo credit should read JONATHAN ERNST/AFP/Getty Images)

U.S. Secretary of State John Kerry gives a statement at the presidential palace in Bogota, Colombia, Friday, Dec. 12, 2014. Kerry said the U.S. supports Colombia's peace talks with the rebels of the Revolutionary Armed Forces of Colombia (FARC). (AP Photo/Fernando Vergara)

ROME, ITALY - DECEMBER 14: Russian Foreign Minister Sergei Lavrov (L) and US Secretary of State John Kerry (R) hold a meeting at Villa Taverna on December 14, 2014 in Rome, Italy. (Photo by U.S. Embassy in Rome/Pool/Anadolu Agency/Getty Images)

US Secretary of State John Kerry delivers a speech in Lima on December 11, 2014, during the UN 20th session of the Conference of the Parties on Climate Change and the 10th session of the Conference of the Parties serving as the Meeting of the Parties to the Kyoto Protocol being held from December 1st to 12th in Lima. AFP PHOTO/CRIS BOURONCLE (Photo credit should read CRIS BOURONCLE/AFP/Getty Images)

US Secretary of State John Kerry delivers a speech in Lima on December 11, 2014, during the UN 20th session of the Conference of the Parties on Climate Change and the 10th session of the Conference of the Parties serving as the Meeting of the Parties to the Kyoto Protocol being held from December 1st to 12th in Lima. AFP PHOTO/CRIS BOURONCLE (Photo credit should read CRIS BOURONCLE/AFP/Getty Images)

US Secretary of State John Kerry (R) speaks with Kazakhstan Foreign Minister Yerlan Idrisov (L) before a working lunch at the State Department in Washington, DC, December 10, 2014. AFP PHOTO/JIM WATSON (Photo credit should read JIM WATSON/AFP/Getty Images)

US Secretary of State John Kerry testifies before the Senate Foreign Relations Committee on Capitol Hill in Washington, DC, December 9, 2014. AFP PHOTO/JIM WATSON (Photo credit should read JIM WATSON/AFP/Getty Images)

U.S. Secretary of State John Kerry arrives at the Royal Terminal of the King Abdulaziz International Airport in Jiddah, Saudi Arabia, Thursday, Sept. 11, 2014. Kerry arrived in Saudi Arabia, on Thursday to try to persuade officials from across the Mideast and Turkey to put aside longstanding rivalries to more vigorously pursue the Islamic State â and, in doing so, ward off a threat that has put the entire region at risk. (AP Photo/Brendan Smialowski, Pool)

U.S. Secretary of State John Kerry, left, talks with attendees before a meeting of the Gulf Arab region at King Abdulaziz International Airport in Jiddah, Saudi Arabia, Thursday, Sept. 11, 2014. Kerry sought to pin down Middle Eastern allies gathering in Saudi Arabia on Thursday on what support they are willing to give to the new U.S. plan to beat back the Islamic State group that has seized large swaths of Iraq and Syria. (AP Photo/Brendan Smialowski, Pool)

U.S. Secretary of State John Kerry, center, poses with his Arab counterparts for a group photo after a meeting with them in Jiddah, Saudi Arabia, Thursday, Sept. 11, 2014. Kerry's visit, on the anniversary of the 9/11 attacks, was aimed at pinning down Middle Eastern allies on what support they are willing to give to U.S. plans to beat back the Islamic State group, which has seized large chunks of Iraq and Syria. (AP Photo/Brendan Smialowski, Pool)

U.S. Secretary of State John Kerry, left, listens to Saudi Arabia's Foreign Minister Saud al-Faisal answer a question after a meeting with Gulf states and other Middle East countries in Jiddah, Saudi Arabia, Thursday, Sept. 11, 2014. Kerry's visit, on the anniversary of the 9/11 attacks, was aimed at pinning down Middle Eastern allies on what support they are willing to give to U.S. plans to beat back the Islamic State group, which has seized large chunks of Iraq and Syria. (AP Photo/Brendan Smialowski, Pool)

U.S. Secretary of State John Kerry makes a statement after a meeting with Gulf states and other Middle East countries in Jiddah, Saudi Arabia, Thursday, Sept. 11, 2014. Kerry's visit, on the anniversary of the 9/11 attacks, was aimed at pinning down Middle Eastern allies on what support they are willing to give to U.S. plans to beat back the Islamic State group, which has seized large chunks of Iraq and Syria. (AP Photo/Brendan Smialowski, Pool)

U.S. Secretary of State John Kerry makes a statement after a meeting with Gulf states and other Middle East countries in Jiddah, Saudi Arabia, Thursday, Sept. 11, 2014. Kerry's visit, on the anniversary of the 9/11 attacks, was aimed at pinning down Middle Eastern allies on what support they are willing to give to U.S. plans to beat back the Islamic State group, which has seized large chunks of Iraq and Syria. (AP Photo/Brendan Smialowski, Pool)

U.S. Secretary of State John Kerry, center, waits for a meeting of the Gulf Arab region at King Abdulaziz International Airport in Jiddah, Saudi Arabia, Thursday, Sept. 11, 2014. Kerry sought to pin down Middle Eastern allies gathering in Saudi Arabia on Thursday on what support they are willing to give to the new U.S. plan to beat back the Islamic State group that has seized large swaths of Iraq and Syria. (AP Photo/Brendan Smialowski, Pool)

U.S. Secretary of State John Kerry, center, attends a meeting of the Gulf Arab region at King Abdulaziz International Airport in Jiddah, Saudi Arabia, Thursday, Sept. 11, 2014. Kerry sought to pin down Middle Eastern allies gathering in Saudi Arabia on Thursday on what support they are willing to give to the new U.S. plan to beat back the Islamic State group that has seized large swaths of Iraq and Syria. (AP Photo/Brendan Smialowski, Pool)

Oman Foreign Minister Yusuf bin Alawi bin Abdullah, right, U.S. Secretary of State John Kerry talk before a meeting of the Gulf Arab region at King Abdulaziz International Airport in Jiddah, Saudi Arabia, Thursday, Sept. 11, 2014. Kerry sought to pin down Middle Eastern allies gathering in Saudi Arabia on Thursday on what support they are willing to give to the new U.S. plan to beat back the Islamic State group that has seized large swaths of Iraq and Syria. (AP Photo/Brendan Smialowski, Pool)

Oman's Foreign Minister Yusuf bin Alawi bin Abdullah, left, and U.S. Secretary of State John Kerry talk before a meeting of the Gulf Arab region at King Abdulaziz International Airport in Jiddah, Saudi Arabia, Thursday, Sept. 11, 2014. Kerry sought to pin down Middle Eastern allies gathering in Saudi Arabia on Thursday on what support they are willing to give to the new U.S. plan to beat back the Islamic State group that has seized large swaths of Iraq and Syria. (AP Photo/Brendan Smialowski, Pool)

U.S. Secretary of State John Kerry waits for the start of a meeting of the Gulf Arab region at King Abdulaziz International Airport in Jiddah, Saudi Arabia, Thursday, Sept. 11, 2014. Kerry sought to pin down Middle Eastern allies gathering in Saudi Arabia on Thursday on what support they are willing to give to the new U.S. plan to beat back the Islamic State group that has seized large swaths of Iraq and Syria. (AP Photo/Brendan Smialowski, Pool)

Bahrain's Minister of Foreign Affairs Shaik Khalid bin Ahmed bin Mohammed Al Khalifa, left, meets with U.S. Secretary of State John Kerry at the Royal Terminal of the King Abdulaziz International Airport in Jiddah, Saudi Arabia, Thursday, Sept. 11, 2014. Kerry arrived in Saudi Arabia, on Thursday to try to persuade officials from across the Mideast and Turkey to put aside longstanding rivalries to more vigorously pursue the Islamic State â and, in doing so, ward off a threat that has put the entire region at risk. (AP Photo/Brendan Smialowski, Pool)

U.S. Secretary of State John Kerry boards his plane in Amman, Jordan, Thursday, Sept. 11, 2014. Kerry arrived in Saudi Arabia, on Thursday to try to persuade officials from across the Mideast and Turkey to put aside longstanding rivalries to more vigorously pursue the Islamic State â and, in doing so, ward off a threat that has put the entire region at risk. (AP Photo/Brendan Smialowski, Pool)

U.S. Secretary of State John Kerry, center left, is greeted by officials with Saudi Foreign Minister Prince Saud al-Faisal, center right, upon his arrival at the Royal Terminal of the King Abdulaziz International Airport in Jiddah, Saudi Arabia, Thursday, Sept. 11, 2014. Kerry arrived in Saudi Arabia, on Thursday to try to persuade officials from across the Mideast and Turkey to put aside longstanding rivalries to more vigorously pursue the Islamic State â and, in doing so, ward off a threat that has put the entire region at risk. (AP Photo/Brendan Smialowski, Pool)

U.S. Secretary of State John Kerry makes a statement before meeting with Saudi Foreign Minister Prince Saud al-Faisal at the Royal Terminal of the King Abdulaziz International Airport in Jiddah, Saudi Arabia, Thursday, Sept. 11, 2014. Kerry arrived in Saudi Arabia, on Thursday to try to persuade officials from across the Mideast and Turkey to put aside longstanding rivalries to more vigorously pursue the Islamic State â and, in doing so, ward off a threat that has put the entire region at risk. (AP Photo/Brendan Smialowski, Pool)

U.S. Secretary of State John Kerry meets with Saudi Foreign Minister Prince Saud al-Faisal at the Royal Terminal of the King Abdulaziz International Airport in Jiddah, Saudi Arabia, Thursday, Sept. 11, 2014. Kerry arrived in Saudi Arabia, on Thursday to try to persuade officials from across the Mideast and Turkey to put aside longstanding rivalries to more vigorously pursue the Islamic State â and, in doing so, ward off a threat that has put the entire region at risk. (AP Photo/Brendan Smialowski, Pool)

U.S. Secretary of State John Kerry, right, walks with Iraqi Foreign Minister Ibrahim al-Jaafari in Baghdad, Iraq, Wednesday, Sept. 10, 2014. Kerry landed in the Iraqi capital just two days after newly sworn Prime Minister Haider al-Abadi seated his top government ministers, a crucial step toward restoring stability in a nation where security has spiraled out of control since the beginning of the year. (AP Photo/Thaier Al-Sudani, Pool)

U.S. Secretary of State John Kerry meets with Iraqi Foreign Minister Ibrahim al-Jaafari in Baghdad, Iraq, Wednesday, Sept. 10, 2014. Kerry landed in the Iraqi capital just two days after newly sworn Prime Minister Haider al-Abadi seated his top government ministers, a crucial step toward restoring stability in a nation where security has spiraled out of control since the beginning of the year. (AP Photo/Thaier Al-Sudani, Pool)

U.S. Secretary of State John Kerry, left, meets with Iraqi Foreign Minister Ibrahim al-Jaafari in Baghdad, Iraq, Wednesday, Sept. 10, 2014. Kerry landed in the Iraqi capital just two days after newly sworn Prime Minister Haider al-Abadi seated his top government ministers, a crucial step toward restoring stability in a nation where security has spiraled out of control since the beginning of the year. (AP Photo/Thaier Al-Sudani, Pool)

U.S. Secretary of State John Kerry meets with Iraqi Foreign Minister Ibrahim al-Jaafari in Baghdad, Iraq, Wednesday, Sept. 10, 2014. Kerry landed in the Iraqi capital just two days after newly sworn Prime Minister Haider al-Abadi seated his top government ministers, a crucial step toward restoring stability in a nation where security has spiraled out of control since the beginning of the year. (AP Photo/Thaier Al-Sudani, Pool)

U.S. Secretary of State John Kerry, right, walks with Iraqi Foreign Minister Ibrahim al-Jaafari in Baghdad, Iraq, Wednesday, Sept. 10, 2014. Kerry landed in the Iraqi capital just two days after newly sworn Prime Minister Haider al-Abadi seated his top government ministers, a crucial step toward restoring stability in a nation where security has spiraled out of control since the beginning of the year. (AP Photo/Thaier Al-Sudani, Pool)

U.S. Secretary of State John Kerry looks out over Baghdad, Iraq, from a helicopter on Wednesday, Sept. 10, 2014. Kerry landed in the Iraqi capital just two days after newly sworn Prime Minister Haider al-Abadi seated his top government ministers, a crucial step toward restoring stability in a nation where security has spiraled out of control since the beginning of the year. (AP Photo/Brendan Smialowski, Pool)

U.S. Secretary of State John Kerry arrives at Baghdad Airport in Baghdad, Iraq, Wednesday, Sept. 10, 2014. Kerry landed in the Iraqi capital just two days after newly sworn Prime Minister Haider al-Abadi seated his top government ministers, a crucial step toward restoring stability in a nation where security has spiraled out of control since the beginning of the year. (AP Photo/Brendan Smialowski, Pool)

JIDDAH, Saudi Arabia (AP) - Key Arab allies promised Thursday to "do their share" to fight Islamic State militants, but NATO member Turkey refused to join in, signaling the struggle the U.S. faces in trying to get front-line nations to put aside their regional animosities and work together to defeat a common enemy.

The Arab states' endorsement of a broad strategy to stop the flow of fighters and funding to the insurgents, and possibly to join military action, came as the CIA doubled its assessment of how many fighters the extremist group can muster.

Both Republicans and Democrats in Congress lined up Thursday behind President Barack Obama's call to combat the militants, a day after he laid out a long-term campaign that would include expanding airstrikes against the fighters in Iraq, launching strikes against them in Syria for the first time and bolstering the Iraqi military and moderate Syrian rebels to allow them to reclaim territory from the militants.

The 10 Mideast allies announced their backing for a strategy to "destroy" the group "wherever it is, including in both Iraq and Syria," following a meeting with U.S. Secretary of State John Kerry in the Red Sea coastal city of Jiddah.

Kerry's visit, on the anniversary of the Sept. 11 attacks, was aimed at pinning down how much support regional allies are willing to give to the U.S. plan to beat back the Islamic State group, which has seized large chunks of Iraq and Syria. Nearly 40 nations have agreed to contribute to what Kerry said would be a worldwide fight to defeat the militants.

In remarks to reporters after the meeting, Kerry noted the "particularly poignant day" for the discussions.

"The devastating consequences of extremist hate remain fresh in the minds of all Americans, and to so many of our friends and allies around the world," Kerry said of the terror attacks on the U.S. 13 years ago. "Those consequences are felt every day here in the Middle East."

Greater regional support is seen as critical to combatting the spread of the Islamic State group, which has proved so ruthless that even al-Qaida severed ties with it earlier this year. New intelligence assessments estimate the extremists can muster between 20,000 and 31,500 fighters across Iraq and Syria, up from a previous figure of 10,000, the CIA said Thursday.

CIA spokesman Ryan Trapani said the new total reflects stronger recruitment by the extremists since June, following battlefield successes and the group's declaration of an Islamic state, or caliphate, on territory under its control.

Thursday's meeting in Jiddah ended with Saudi Arabia, other Gulf states, Egypt, Iraq, Jordan and Lebanon pledging to stand against terrorism. They promised steps including stopping fighters and funding, repudiating the Islamic State group's ideology, providing humanitarian aid and "as appropriate, joining in the many aspects of a coordinated military campaign."

They also agreed to boost support for the new Iraqi government as it tries to unite its citizens in the fight against the militants. Saudi Foreign Minister Prince Saud al-Faisal said coalition members agreed to share responsibilities for fighting the Islamic State group, as well as to "be serious and continuous in our action to eliminate and wipe out all these terrorist organizations."

Turkey attended the meeting but did not sign the final communique.

The NATO ally had been asked to secure its borders to prevent oil smuggling out of Iraq and Syria and keep foreign fighters from heading in. But Ankara has been reluctant to take a prominent role in the coalition, in part out of concern for the 49 Turkish citizens who were kidnapped from the Turkish consulate in the northern Iraqi city of Mosul when it was overrun by Islamic State fighters in June.

U.S. officials played down Turkey's absence from the communique, noting that the Turkish government is still extremely concerned about the fate of its diplomats. A senior State Department official predicted the U.S. will continue to work with Turkey to repel the insurgent threat, and said Ankara is in a difficult position as it tries to protect the hostages. The official was not authorized to discuss the sensitive negotiations by name and spoke on condition of anonymity.

Squabbling among Washington's allies in the region has complicated efforts to present a united front to beat back the militants.

Saudi Arabia, the Emirates and Egypt are at odds with Qatar and Turkey because of the latter two countries' support for the Muslim Brotherhood and other Islamist groups in the region.

Egypt's foreign minister, Sameh Shukri, emphasized that rift in his opening remarks, saying regional chaos is the result of a number of factors, including the tolerance of some in the region and the West for "so-called political Islam" - a clear dig at supporters of the Brotherhood.

American officials have voiced concerns too about the willingness of Kuwait and Qatar to crack down on private fundraising for extremist groups.

Some Gulf states could in theory take an active role in helping with airstrikes, as the United Arab Emirates and Qatar did in the U.S.-led aerial campaign over Libya in 2011 that helped lead to the ouster of Moammar Gadhafi. Gulf nations could also assist with arms, training, intelligence and logistics.

Salman Shaikh, the director of the Brookings Doha Center in Qatar, said Thursday's meeting in Jiddah was important because it signaled a U.S. reengagement in the region - something many Mideast allies feel has been lacking under the Obama administration.

"How the U.S. can play this role will be absolutely crucial," he said. "It has to act as a keen leader for its friends and allies, but also act as a referee between Saudi Arabia, Turkey and Iran, particularly when it comes to the issue of Iraq and the issue of Syria."

In Congress, Republicans and Democrats coalesced behind Obama's call for authority to train and equip moderate Syrian rebels opposed to Islamic State militants.

"We ought to give the president what he's asking for," House Speaker John Boehner said, although he swiftly added that many Republicans believe the Democratic commander in chief's strategy is too tepid to crush militants who have overrun parts of Iraq and Syria and beheaded two American journalists.

U.S. officials said retired Marine Gen. John Allen is to coordinate the broad international effort. Allen, who has been serving as a security adviser to Kerry, is expected to work with the nearly 40 nations around the world who have agreed to join the fight and help them coordinate what each will contribute, said the officials, who spoke on condition of anonymity because they were not authorized to discuss the appointment ahead of an announcement.

Allen has vast experience coordinating international allies on the warfront. As deputy commander in Iraq's Anbar province from 2006 to 2008, he worked with Arab partners on organizing the Sunni uprising against al-Qaida, and also served as the top U.S. commander in Afghanistan from 2011 to 2013.

The U.S. already has launched more than 150 airstrikes against militants in Iraq over the past month, and has sent military advisers and millions of dollars in humanitarian aid, including an additional $48 million announced Wednesday.

The Mideast diplomatic push comes ahead of a conference set for Monday in Paris on how to stabilize Iraq. That meeting will include officials from the U.S., Britain, France, Russia and China, and could also include other nations, possibly even Iran.